UNIVERSITY    OF    CALIFORNIA     AGRICULTURAL    EXPERIMENT   STATION 
COLLEGE   OF   AGRICULTURE  ™'™  WHEELER"  p— T 

THOMAS    FORSYTH    HUNT,    Dean  and   Oirector 

BERKELEY  h.  e.  van  norman,  vice-director  *no  dean 

University  Farm  School 

CIRCULAR  No.  198 

April,  1918 

SYRUP  FROM  SWEET  SORGHUM 

By  W.  V.  CEUESS 


In  a  recent  publication,  Hunt1  makes  the  following  statement: 
"In  California,  perhaps  the  most  important  single  item  tending  to 
increase  animal  production,  including  dairy  products,  is  the  building 
of  silos.  This  is  not  because  there  are  any  magical  food  qualities  in 
silage,  but  chiefly  because  if  a  stockman  or  dairyman  has  a  silo,  he  will 
raise  something  with  which  to  fill  it. . . .  It  is  likely  to  be  Indian  corn, 
sweet  sorghum,  or  Egyptian  corn.  The  investigations  at  the  Univer- 
sity Farm  at  Davis  indicate  that  the  sweet  sorghums  are  well  adapted 
for  silage  purposes. ' ' 

Woll  and  Voorhies2  have  found  that  sweet  sorghum  silage,  per  unit 
of  dry  matter  furnished  in  the  rations,  proved  more  efficient  for  milk 
production  than  other  forms  of  silage  tested. 

Since  it  is  a  proven  fact  that  silage  is  a  very  important  factor  in 
animal  and  milk  production,  and  since  the  practical  feeding  tests 
noted  above  have  shown  the  superiority  of  sweet  sorghum  silage,  it  is 
probable  that  a  considerable  acreage  will  be  planted  to  sweet  sorghum 
this  season.  At  the  present  time,  there  is  a  shortage  of  sugar.  It  is 
therefore  desirable,  wherever  possible,  to  increase  the  production  of 
sugar  substitutes.  One  of  the  most  acceptable  substitutes  for  some 
purposes  is  sorghum  syrup.3 

If  sweet  sorghum  is  planted  for  silage  on  irrigated  or  sub-irrigated 
land,  it  will  usually  be  a  simple  matter  to  plant  -from  one  to  five  acres 
more  for  sorghum  syrup  manufacture.  Should  conditions  at  the  time 
of  harvesting  warrant  it,  this  sorghum  could  then  be  used  for  syrup 
making.    Otherwise,  it  could  be  used  as  forage. 

This  publication  describes  methods  of  making  syrup  from  sweet 
sorghum,   and  more  particularly,   such  methods   as   are   adapted   to 

i  Circular  187,  University  of  California  Experiment  Station,  Utilizing  the 
Sorghums,  by  Thomas  Forsyth  Hunt. 

2  Bulletin  282,  University  of  California  Experiment  Station,  Trials  with  Cali- 
fornia Silage  Crops  for  Dairy  Cows,  by  F.  W.  Woll  and  E.  C.  Voorhies. 

s  The  Division  of  Viticulture  is  also  developing  a  promising  method  of  pro- 
ducing syrup  from  cull  table  grapes,  second-crop  muscat  grapes  and  other  products 
of  the  vineyard  which  either  go  to  waste  or  are  incompletely  used  as  food  material. 
It  appears  probable  that  syrup  from  grapes  can  be  produced  at  less  expense  for 
labor  per  unit  of  sugar  than  from  sorghum. 


small-scale  operations.  In  many  localities  where  sorghum  will  be 
grown,  some  one  will  be  found  who  has  made  sorghum  syrup  and  can 
direct  others  in  operating  the  machinery  used.  Where  no  one  with 
experience  in  syrup  manufacture  is  available,  the  university  will 
undertake  to  give  what  instruction  may  be  needed  in  addition  to  the 
information  contained  here. 

Varieties  of  Sorghum  for  Syrup. — Madson4  has  found  that  late 
sweet  sorghums  produce  more  gross  weight  per  acre  than  early  varie- 
ties and  that  the  yield  is  in  some  measure  proportional  to  the  length 
of  the  growing  season.  Where  seed  can  be  obtained,  these  late  high- 
yielding  varieties  will  be  grown  for  silage,  in  preference  to  the  early 
varieties.  Other  things  being  equal,  varieties  producing  the  greatest 
yield  of  cane  will  also  produce  the  greatest  yield  of  sj^rup. 

Of  the  varieties  tested,  Madson  found  that  the  Honey  Sorghum 
gave  the  highest  yield  per  acre,  in  experiments  extending  over  three 
seasons  at  Davis.  In  1915,  it  yielded  over  30  tons  per  acre,  and  in 
1914  and  1916,  over  twenty-six  tons  per  acre.  Other  good  varieties 
tested  at  Davis  are  Red  Amber,  Orange  Sorghum,  and  Planters 
Sorghum.  Early  Amber  and  other  early  varieties  gave  poor  yields. 
Orange  sorghum  has  given  good  results  for  syrup  manufacture  at 
Riverbank,  California,  where  it  was  grown  commercially  by  L.  R. 
Bright.    Black  Amber  was  found  unsatisfactory  by  Mr.  Bright. 

Sweet  Sorghum  Culture. — The  planting"  and  cultivation  of  sweet 
sorghums  are  practically  the  same  as  for  the  grain  sorghums,  as  de- 
scribed by  Madson  in  Bulletin  278  of  this  station.  If  any  great 
quantity  of  cane  is  to  be  made  into  syrup  it  should  be  planted  at 
intervals  of  two  weeks  to  insure  a  supply  of  cane  over  a  considerable 
period  of  crushing.  Dates  of  planting  suggested  are  April  1,  April  15, 
May  1,  May  15,  and  May  30. 

Sweet  sorghum  for  syrup  should  be  well  supplied  with  water  by 
irrigation  or  by  sub-irrigation.  The  yield  of  juice  will  be  small  and 
the  cane  difficult  to  crush  if  the  moisture  is  insufficient. 

Harvesting. — The  sorghum  is  best  for  syrup  making  from  the  time 
when  the  seed  has  reached  the  hard  dough  stage  to  the  time  of  its  dry 
stage.  If  the  cane  is  cut  too  green,  the  syrup  will  have  an  unripe 
taste ;  if  cut  too  ripe,  the  cane  will  yield  a  juice  of  inferior  flavor  and 
difficult  to  clarify. 

The  cane  must  be  worked  up  within  one  or  two  days  of  the  time  it 
is  cut.  If  held  longer,  it  will  become  too  dry,  or  if  placed  in  piles  to 
prevent  drying,  it  will  become  sour  through  "heating"  (fermenta- 
tion). 


4  B.  A.  Madson,  Project  283,  University  of  California  Experiment  Station. 


The  leaves  should  be  stripped  from  the  cane  before  it  is  cut.  This 
can  be  done  by  special  tools  made  for  the  purpose,  or  a  wooden 
''sword"  made  from  a  barrel  stave  will  answer  the  purpose  very  well. 
Suckers  should  also  be  removed.  •  Leaves  and  suckers  injure  the  flavor 
and  render  the  juice  difficult  to  clarify. 

In  California,  the  cutting  of  the  cane  will,  in  most  cases,  be  done 
by  hand.  Corn  binders  can  be  used.  The  cane  is  cut  six  to  eight 
inches  above  the  ground  and  stacked  with  the  heads  all  in  the  same 
direction. 


(Courtesy  of  Blyiner  Iron  Works) 
Fig.  1. — Horse-power  sorghum  mill. 

The  heads  must  be  cut  from  the  canes.  This  can  be  done  in  the 
field  and  the  heads  thrown  into  piles  to  be  collected  later. 

The  leaves  from  stripping  are  good  for  forage  and  silage.  Under 
normal  conditions  they  will  amount  to  about  200  pounds  per  ton  of 
sorghum.  They  should  be  gathered  as  soon  after  stripping  as  possible 
to  avoid  excessive  drying.  The  seed  is  a  very  important  by-product 
and  should  amount  to  at  least  1000  pounds  per  acre,  worth  at  present 
prices  3c  a  pound  or  more  (see  p.  ??).  The  seed  can  be  dried  and 
threshed  as  described  for  grain  sorghum  by  Madson  in  Bulletin  278 
of  this  station. 

Crushing  and  Pressing  the  Cane. — The  stripped  and  topped  cane 
must  be  subjected  to  very  heavy  pressure  to  extract  the  juice.     The 


usual  method  is  by  passing  the  cane  between  two  or  three  heavy  iron 
rollers,  set  at  such  a  distance  apart  that  the  cane  is  crushed  and  most 
of  the  juice  is  pressed  out  at  one  operation. 

There  are  a  number  of  forms  of  sorghum  mills.  Some  are  operated 
by  horse-power,  large  ones  by  gasoline  engines,  electric  motors,  or 
steam  power,  and  very  small  mills  may  be  had  that  are  operated  by 
hand  power.  For  the  small  syrup  factory  the  horse-power  mills  have 
sufficient  capacity. 

Most  horse-power  mills  are  equipped  with  three  upright  rolls, 
6  to  12  inches  in  length  and  6  to  14  inches  in  diameter.  They  are 
operated  by  a  sweep  attached  to  the  top  of  the  mill.  (See  figs.  1  and 
2.)  These  mills  have  a  capacity  of  from  2  to  18  tons  per  day.  Their 
price  varies  from  $25  to  $320. 


Fig.  2.- — Horse-power  mill  on  ranch  of  L.  E.  Bright,  Eiverbank.     Mill  is  set  well 
off  ground  so  that  juice  may  be  received  in  barrels. 


The  engine-power  mills  are  equipped  with  horizontal  rolls.  (See 
fig.  3.)  Their  capacity  varies  from  10  to  60  tons  per  12  hours,  and 
their  prices  from  $75  to  $2000  or  more. 

The  rolls  should  be  set  at  such  a  distance  apart  and  the  cane  should 
be  fed  at  such  a  rate  that  the  maximum  amount  of  juice  is  obtained. 
This  can  be  determined  by  trial.  For  rapid  feeding  the  rolls  will  be 
set  farther  apart  than  for  slow  feeding  of  the  mill.  With  sorghum  of 
average  juice  content,  at  least  100  gallons  of  juice  should  be  obtained 
per  ton  of  stripped  cane.  This  figure  can  be  used  as  an  indication 
of  the  efficiency  of  the  mill. 

Second  Pressing. — The  pressed  cane  may  be  moistened  with  water 
and  pressed  a  second  time.  This  will  yield  a  juice  lower  in  sugar 
content  and  inferior  in  quality  to  the  first  pressing.     It  should  be 


concentrated  and  kept  separately.     If  a  sufficient  supply  of  cane  is 
available,  the  second  pressing  should  be  omitted. 

Straining  the  Juice. — The  juice  from  the  press  is  received  in  a 
tank  or  barrel.  It  should  be  strained  through  a  fine  screen  to  remove 
coarse  particles  of  pulp. 


(Courtesy  of  Blymer  Iron  Works) 
Fig.  3. — Power  sorghum  mill.     Electric  motor  or  gasoline  power  may  be  used. 

Settling  the  Juice. — Before  going  to  the  evaporating  pan,  the  juice 
should  be  permitted  to  deposit  as  much  of  its  sediment  as  possible. 
This  fine  sediment,  if  left  in  the  juice,  causes  the  latter  to  stick  to  the 
pan  and  burn.     A  shallow  pan,  such  as  that  shown  in  figure  4,  and 


~ 


Fig.  4. — Settling  trough  to  be  placed   between  mill  and  receiving  barrel. 

equipped  with  "riffles"  or  transverse  strips  across  the  bottom  as 
shown,  and  transverse  "baffles"  or  strips  so  placed  that  the  juice  will 
pass  beneath  them,  will  remove  a  great  deal  of  the  suspended  material. 


This  pan  may  be  placed  beneath  the  crusher.  The  juice  flows  from 
the  crusher  into  the  pan  and  as  it  traverses  the  pan  the  settlings  are 
held  by  the  bottom  strips,  while  floating  material  is  held  by  the  upper 
strips.  The  settled  juice  flows  out  through  the  spigot  at  the  end  of 
the  pan  into  a  barrel  or  tank.  This  spigot  is  set  above  the  bottom  of 
the  pan  to  avoid  draining  the  settlings.  The  settling  pan  or  trough 
may  be  made  of  wood  and  is  about  4  to  6  inches  deep.  The  one  shown 
in  the  figure  is  about  4  feet  long.  It  is  more  effective  if  10  to  20  feet 
long  and  equipped  with  a  larger  number  of  "riffle"  and  "baffle" 
strips. 

In  addition  to  the  settling  device  described  above,  several  shallow 
tanks  or  vats  about  2  feet  deep  should  be  provided  for  further  settling 
of  the  juice  for  three  or  four  hours  before  it  is  concentrated.  The 
type  of  tank  shown  in  figure  5  can  be  used  for  this  purpose. 


Fig.  5. — Settling  tank  for  juice  or  syrup. 

Clearing  the  Juice  by  Heating  and  Settling. — The  juice  may  be 
made  still  clearer  by  heating  it  to  boiling  and  allowing  it  to  stand 
several  hours  after  the  heat  is  turned  off.  A  coagulation  of  the 
albuminous  matter  occurs  during  heating.  Part  of  this  comes  to  the 
surface  and  can  be  skimmed  off.  Part  settles  and  is  separated  by 
drawing  off  the  juice  above  the  sediment.  An  extra  tank  should  be 
provided  for  this  settling  process.  The  clear  juice  is  then  ready  for 
concentration. 

The  sediment  and  skimmings  may  be  strained  through  a  cloth  bag 
until  clear  enough  for  concentration  or  may  be  mixed  with  the  pressed 
cane  to  be  used  for  forage  or  silage.  This  material  should  not  be 
wasted. 

Clearing  and  Neutralizing  the  Juice  with  Precipitated  Chalk  or 
Whiting. — If  the  juice  is  very  sour  and  does  not  settle  well  after 
heating  it  may  often  be  improved  by  adding  precipitated  chalk  or  a 


good  grade  of  whiting  (carbonate  of  lime)  in  small  amounts  to  the 
boiling  juice  until  the  juice  will  no  longer  turn  a  piece  of  blue  litmus 
paper  red.  The  amount  used  will  be  about  one  half  to  one  ounce  of 
whiting  per  gallon.  Only  the  best  whiting  should  be  used.  An  excess 
will  do  no  harm.  The  treated  juice  is  allowed  to  settle  several  hours 
after  heating  and  before  drawing  it  off  from  the  sediment  for  con- 
centration. It  is  usually  not  necessary  or  advisable  to  use  whiting  or 
chalk  for  small-scale  operations. 

Clearing  by  Filtering. — "Where  small  quantities  of  syrup  are  to 
be  made,  the  fresh  juice  may  be  cleared  by  heating  to  boiling  followed 
by  filtering  while  hot  through  a  filter  bag  made  of  felt  or  heavy  cloth. 
The  process  is,  however,  exceedingly  slow  and  will  usually  not  repay 
the  effort.  On  a  very  large  scale  it  would  be  possible  to  use  a  force 
pump  and  a  large  filter  press  to  clear  the  hot  juice.  Another  method 
of  clearing  the  juice  is  to  concentrate  it  to  about  one-half  its  original 
volume  and  then  filter  it  through  sand  or  excelsior.  A  shallow  box 
4  to  6  inches  deep  filled  with  sand  may  be  used.  Clay  and  milk  of  lime 
have  been  used  for  clarifying  the  juice,  but  their  use  is  not  recom- 
mended for  the  beginner. 

Concentration  of  the  Juice. — After  most  of  the  sediment  has  been 
removed,  the  juice  is  ready  for  evaporation  to  a  syrup.  This  may  be 
done  in  any  one  of  several  forms  of  evaporators  described  below. 

1.  By  Use  of  Iron  Kettle. — The  simplest  form  of  syrup  evaporator 
is  a  cast-iron  kettle  heated  with  a  wood  fire.  This  apparatus  will  give 
a  very  dark  colored  syrup  because  of  the  long  heating  necessary  and 
because  the  juice  acts  upon  the  iron  of  the  kettle,  forming  a  dark 


(Courtesy  of  Blymer  Iron  Works)    , 
Fig.  6. — Continuous  pan  evaporator.     This  is  the  most  common  type  of  pan  used. 


8 

colored  compound.    It  should  be  used  only  where  a  more  satisfactory 
evaporator  can  not  be  obtained. 

2.  By  Use  of  Continuous  Pan  and  Portable  Fire  Box. — A  very 
satisfactory  evaporating  outfit  for  small-scale  operations  is  shown  in 
figures  6  and  7.  The  evaporating  pan  shown  in  figure  6  is  made  of 
galvanized  iron  or  of  copper.  It  varies  in  length  from  5  to  15  feet. 
The  longer  pans  are  more  satisfactory.  This  pan  is  placed  over  the 
fire  box  shown  in  figure  7.  This  fire  box  is  of  the  same  length  as 
the  pan. 


(Courtesy  of  Blymer  Iron  Works) 
Fig.  7. — Portable  fire  box  for  use  with  pan  shown  in  preceding  figure. 

The  fire  box  should  be  lined  with  fire  brick  or  good  clay  to  protect 
the  walls  and  check  radiation  of  heat.  This  must  be  done  after  the 
fire  box  is  received  from  the  manufacturer. 

The  clear  juice  is  allowed  to  run  in  at  the  upper  end  of  the  pan 
from  a  tank  or  barrel  placed  above  it  as  in  figure  9.  The  fire  and 
the  flow  of  juice  are  so  regulated  that  syrup  of  the  proper  per  cent 
of  sugar  will  flow  from  the  lower  end.  Where  very  short  pans  (6  to  8 
feet  in  length)  are  used,  it  is  difficult  to  maintain  a  constant  flow  of 
syrup  from  the  pan  and  it  often  becomes  necessary  to  close  the  syrup 
outlet  for  a  few  minutes  to  permit  the  syrup  to  become  of  the  desired 
density. 

Great  care  must  be  observed  in  keeping  the  bottom  of  the  pan 
covered  with  juice  at  all  times  to  prevent  scorching.  During  boiling, 
the  depth  of  liquid  in  the  pan  should  not  be  too  great,  otherwise  the 


great  length  of  time  necessary  to  concentrate  the  juice  will  result  in 
darkening.  The  fire  should  be  vigorous.  Light,  quick-burning  wood 
is  best  for  use  with  this  style  of  furnace.  The  fire  should  be  especially 
hot  at  the  stack  end  of  the  furnace  where  the  final  boiling  of  the 
syrup  takes  place.  The  more  intense  the  fire,  however,  the  more 
care  must  be  taken  to  prevent  scorching  of  the  syrup.  Coagulated 
albuminous  and  other  materials  come  to  the  surface  during  boiling. 
These  should  be  skimmed  off.  The  skimmer  shown  in  figure  8  is  useful 
for  this  purpose. 


(From  Farmers'  Bull.  477,  U.S.D.A. 
Fig.   8. — Skimmer  used  during  the   concentration   of   the   juice. 


Darkening  is  often  due  to  boiling  the  syrup  to  too  high  a  sugar 
content;  boiling  should  stop  when  the  syrup  has  become  rich  enough 
in  sugar  to  keep  without  sterilization.  This  point  can  be  determined 
as  described  in  the  following  paragraph.  When  the  last  juice  has 
gone  into  the  pan  it  should  be  followed  with  water  to  prevent  scorch- 
ing the  juice  that  remains. 

3.  Testing  the  Syrup. — An  experienced  syrup  maker  can  judge 
when  the  syrup  has  been  concentrated  enough,  by  the  general  appear- 


(From  Farmers'  Bull.  477,  U.S.D.A.) 

Yig,   9. — Continuous  evaporator   mounted   on   permanent   brick   furnace.      This   is 
the  most  satisfactory  method  of  mounting  the  large  pans. 


10 


ance  and  behavior  of  the  syrup ;  but  even  his  judgment  is  not  always 
reliable.  The  point  at  which  the  boiling  is  sufficient  can  be  easily  and 
accurately  determined  by  use  of  a  Baume  sj^rup  hydrometer,  or  a 
Balling  hydrometer. 

The  hydrometer  consists  of  a  glass  tube  weighted  at  one  end  with 
shot  or  mercur}^  and  carrying  a  narrower  tube  or  stem  at  the  upper 


IOJ 


20 


30j 


4PJ 

6pJ 


(From  Farmers'  Bull.  477,  U.S.D.A.) 


Fig.  10. — Baume  Syrup  Hydrometer  with  Tin  Cylinder  to  Hold  Syrup  for  Testing. 
end  marked  in  degrees  Baume  or  Balling.5  The  whole  instrument  is 
about  12  inches  long.  A  tin,  copper,  or  glass  cylinder  about  1% 
inches  in  diameter  and  about  12  inches  in  height  as  shown  in  figure  10 
will  be  needed  to  hold  the  syrup  sample. 

Pour  the  hot  syrup  into  the  cylinder,  filling  it  almost  full.  If 
the  syrup  is  frothy,  fill  the  cylinder  to  overflowing  so  that  the  bubbles 
will  not  interfere. 


5  Some  syrup  hydrometers  are  marked  in  degrees  Brix.     This  is  the  same  as 
Balling. 


11 

Insert  the  hydrometer  into  the  hot  syrup.  Read  the  degree  indi- 
cated on  the  hydrometer  stem  at  the  surface  of  the  liquid.  If  the 
syrup  is  hot,  that  is,  tested  within  two  or  three  minutes  from  the 
time  it  is  taken  from  the  pan,  it  should  give  on  the  Baume  hydrometer 
more  than  36°  and  less  than  40°  ;  and  on  the  Balling  or  Brix  hydro- 
meter between  65°  and  73°.  Hot  syrup  gives  a  lower  reading  than 
the  same  syrup  after  it  has  cooled.  For  cold  syrup  the  above  figures- 
will  be  38°  to  42°  Baume  and  70°  to  78°  Balling  or  Brix.  These 
figures  may  be  used  in  testing  the  syrup  after  it  has  cooled,  in  order 
to  check  the  tests  made  during  evaporation.  Tests  are  valuable  in 
making  blends  of  syrup  that  has  been  concentrated  too  far  with  syrup 
too  low  in  sugar  content. 

Syrup  below  70°  Balling  or  Brix,  or  below  38°  Baume  (tested 
on  cold  syrup)  is  very  apt  to  mold  or  ferment.  Syrup  very  high  in 
sugar  may  crystallize.  Thirty-eight  degrees  Baume  in  cold  syrup  is 
equivalent  to  36°  Baume  in  hot  syrup,  and  70°  Balling  or  Brix  cold 
is  equivalent  to  65°  in  hot  syrup. 

4.  By  Use  of  Continuous  Pan  and  Permanent  Furnace. — Where 
long  pans  (12  to  15  feet)  are  used,  they  are  usually  mounted  upon  a 
brick  furnace.  Figure  9  shows  such  an  evaporating  outfit  equipped 
for  wood  fuel.  Under  most  California  conditions,  wood  may  be  hard 
to  obtain  and  crude  oil  as  fuel  would  probably  be  less  expensive  and 
as  satisfactory  as  wood.  Forced  feed  for  the  oil  would  perhaps  be 
necessary  although  the  type  of  crude  oil  burner  used  for  heating 
solutions  used  in  dipping  grapes  for  raisin  making  and  in  furnishing 
heat  to  fruit  evaporators  might  prove  satisfactory. 

The  pressed  cane  may  be  air-dried  and  used  for  fuel.  A  special 
large  open  grate  is  needed  when  this  fuel  is  used.  Companies  that 
furnish  mills  and  evaporators  can  furnish  grates  for  this  purpose, 
with  directions  for  their  installation  and  use. 

The  operation  of  this  type  of  outfit  is  similar  to  that  of  the  portable 
outfit  described  under  section  2.  A  15-foot  pan  can  be  made  to  produce 
200  gallons  of  syrup  per  12  hours,  and  a  6-foot  pan  15  to  30  gallons. 

5.  Steam  Evaporators. — Evaporators  heated  by  high-pressure 
steam  may  be  had.  The  steam  evaporator  consists  of  a  long,  shallow, 
wooden  trough  with  a  copper  steam  coil  in  the  bottom.  The  juice 
enters  at  one  end  and  as  it  flows  over  the  coil  to  the  lower  end  it  is 
concentrated  to  a  syrup.  These  evaporators  produce  excellent  syrup 
of  light  color  when  properly  operated.  Steam  evaporators  will  require 
8  to  40  horsepower  steam  boilers.  They  are  suitable  for  large  estab- 
lishments. A  steam  evaporator  will  produce  100  to  600  gallons  of 
syrup  per  12  hours,  depending  on  its  size. 


12 


6.  Vacuum  Pans. — Where  a  very  large  permanent  installation  is 
contemplated,  the  installation  of  the  vacuum  system  of  evaporation 
should  .be  considered.  The  vacuum  pan  for  syrup  is  usually  an 
enclosed  steam-heated  copper  kettle.  Pans  of  commercial  size  vary 
from  $1000  to  $10,000  in  price  and  will  produce  from  300  to  3000 
gallons  of  syrup  per  12  hours.  A  steam  plant,  vacuum  pump  and  a 
large  supply  of  water  for  condensation  are  necessary  for  their  use. 


(Courtesy  of  Golden  Foundry  Co.) 
Fig.   11. — A  steam   syrup   evaporator. 

Storing  and  Canning  the  Syrup. — The  finished  syrup  may  be 
stored  in  barrels.  It  is  usually  marketed  in  gallon  or  smaller  cans. 
At  the  present  time  cans  are  very  difficult  to  obtain.  The  syrup  may 
also  be  sold  in  bulk  in  barrels  or  in  small  kegs. 


OUTLINE    OF    PROCESS    RECOMMENDED    FOR    THE    SMALL-SCALE 
MANUFACTURE    OF    SORGHUM    SYRUP 

1.  Equipment :  Small  horse-power  mill ;  galvanized  iron  or  copper 
evaporating  pan  8  to  10  feet  long;  portable  furnace  for  pan;  settling 
pan  about  6  to  8  feet  long  at  crusher  (see  fig.  4)  ;  settling  tank  of 
about  50  gallons  capacity  (fig.  5)  ;  two  open  50-gallon  barrels  for 
juice;  receiving  and  settling  tank  for  syrup,  25  gallons  (fig.  5); 
skimmer  for  use  during  boiling  of  syrup ;  30  or  25-gallon  open  barrel 
or  wooden  tub  with  spigot  to  be  placed  above  pan  for  juice  supply 
for  pan  (see  fig.  9)  ;  several  buckets  and  dippers. 

2.  Harvesting :  Strip  off  leaves  when  seed  is  almost  ripe ;  cut  canes 
at  6  to  8  inches  from  ground.  Cut  off  heads.  Haul  cane  to  mill  at  once. 

3.  Press  as  soon  after  cutting  as  possible. 


13 

4.  Pass  juice  from  the  mill  through  settling  pan  below  mill  to 
settling  tank. 

5.  Heat  to  boiling  and  allow  to  stand  four  or  five  hours  after 
heat  is  turned  off.  Skim  off  floating  material.  The  heating  can  be 
done  in  the  evaporating  pan  and  the  heated  juice  transferred  to  a 
barrel  or  tank  for  settling. 

6.  Draw  off  settled  juice  as  clear  as  possible  from  sediment.  The 
sediment  may  be  strained  and  used  for  syrup  or  may  be  used  for 
stock  feed. 

7.  Fill  the  evaporating  pan  with  the  settled  juice  and  boil  down 
to  a  syrup.  Allow  syrup  to  flow  from  the  pan  and  the  juice  to  flow 
into  the  pan  at  such  a  rate  that  the  syrup  tests  when  hot  between  36° 
and  40°  Baume  or  between  65°  and  73°  Balling  or  Brix.    (See  fig.  10.) 

8.  Allow  syrup  to  settle  four  or  five  hours. 

9.  Fill  into  syrup  cans  or  kegs. 

COST   OF    EQUIPMENT    FOR    SORGHUM-SYRUP    MANUFACTURE 

Case  A. — Smallest  Factory-Made  Outfit 

1.  One  small  horse-power  cane  mill  of  2-3  tons  capacity  per  day.   f.o.b. 

Eastern  point $32.50 

2.  One  rocker  furnace,  Cook's  pattern,  66  inches,  f.o.b.  Eastern  point 17.65 

3.  One  galvanized  iron  Cook's  pattern  evaporator,  66  inches 8.80 

4.  Freight  to  any  point  in  California  (freight  rate  in  1914)  28.00 

$86.95 

In  1914  the  cost  of  this  whole  outfit  delivered  in  California  was 
$60.  The  freight  charge  given  may  have  increased  to  about  $40  for 
this  year,  and  if  so,  the  cost  of  the  entire  plant  would  be  $100. 

Its  capacity  per  day  of  12  hours  is  about  20  gallons  of  syrup,  or 
per  season  of  40  days,  800  gallons.  This  is  its  maximum  capacity 
unless  run  longer  than  12  hours  a  day. 

Case  B. — Plant  with  Capacity  of  160  Gallons  Syrup  per  12  Hours 

1.  One  power  cane  mill  with  capacity  of  2  tons  of  cane  per  hour;  4  h.p.— .$100.00 

2.  One  Cook  evaporator,  galvanized  iron,  180  inches  long 24.00 

3.  One  No.  5  furnace  front  and  grate  28  X  35  inches;    door  opening  to 

furnace,    9V2  X  20y2    inches 14.45 

4.  sBricks    (2500)    and  lime    (3  barrels)    for  building  furnace  for  evapo- 

rator, belt  for  motor,  juice  receptable  above  pan   (100-gallon  tank 
with  spigot),  syrup  receiver  (100-gallon  tank),  juice  pipes,  skimmer, 

three  20-gallon  fiber  tubs,  %  dozen  3-gallon  fiber  buckets 125.00 

5.  One  5-h.p.  electric  motor  or  gasoline  engine 150.00 

6.  One  hand-power  pump  (Woodin  and  Little),  or  similar  type 25.00 

7.  Freight  on  mill,  pan,  and  furnace  door  from  East 50.00 

$510.45 
6  Estimate  for  cost  of  furnace  from  Bui.  486,  U.  S.  Dept.  Agr. 


14 


ESTIMATE     OF    APPROXIMATE     RETURNS     FROM     SORGHUM     SYRUP 

Assumed: 

1.  Yield  of  14  tons  per  acre,  equal  to  12  tons  stripped  cane. 

2.  Yield  of  11  gallons  of  syrup  per  ton  of  stripped  cane  (or  132 
gallons  per  acre). 

3.  A  season  of  30  working  days. 

4.  That  factory  has  an  average  capacity  of  160  gallons  to  170 
gallons  per  day  or  about  5000  gallons  for  the  season.  This  would 
represent  about  40  acres  of  sorghum. 

The  cost  of  producing  the  syrup  would  be  approximately  as  fol- 
lows: 

Estimated  Cost  of  Production 

The  costs  per  acre  for  plowing,  seeding,  irrigating,  cultivating,  and 
cutting  are  taken  from  R.  L.  Adams,  Agronomy  Project  337,  page  104. 

Cost  per 
Cost  per  ton  whole 

. acre  cane 

1.  Fall  plowing   (Adams) $1.75  $0,125 

2.  Spring    plowing    (Adams)  1.25  .089 

3.  Preparation  of  seed  bed  (Adams)  1.75  .125 

4.  Cost  of  seed    (Adams)  25  .018 

5.  Planting    (Adams)    30  .021 

6.  Cultivating  and  furrowing   (Adams)  2.50  .178 

7.  Water    (Adams)    1.50  .107 

8.  Applying  water    (Adams)  .75  .053 

9.  Cutting  by  hand    (Adams)  1.75  .125 

10.  Hauling  at  50c  per  ton   (estimated)  -         7.00  .500 

11.  Stripping,  topping  cane  and  threshing  and  dry- 

ing seed    (estimated)  20.00  1.429 

12.  Taxes  and  insurance  on  land  (Adams)  2.50  .178 

13.  Crushing  cane  and  concentrating  juice  at  fac- 

tory at  18c  per  gallon 24.00  1.715 

14.  Cost  of  cans,  shipping  boxes,  and  labor  for  can- 

ning (estimate  by  L.  E.  Bright)  at  25c  per 

gallon    33.00  2.357 

$98.30  $7,020 

Cost  per  gallon,  $0,746. 

Value  of  Products  at  Current  Prices 

Value  per 
Value  per  ton  of  whole 

acre  cane 

1.  132  gallons  syrup  at  $1  per  gallon $132.00  $9.43 

2.  1400  pounds  seed  at  3c  lb 42.00  3.00 

3.  2500  lbs.  leaves  at  $5  per  ton 6.25  .43 

4.  Pressed  cane    (bagasse),   5  tons  at  $2.50,  for 

forage  12.50  .89 

Total $192.75  $13.75 

Value  per  gallon  of  syrup,  $1.44. 


15 

Approximate  Profit 

1.  Per  acre,  $192.75  less  $98.30 $94.45 

2.  Per  ton  of  whole  cane,  $13.75  less  $7.02 6.73 

3.  Per  gallon  of  syrup,  if  value  of  by-products   (seed,  leaves,  and  cane) 

is  deducted  from  cost  of  manufacture,  $1.44  less  $0.75 .69 

4.  Per  gallon  of  syrup,  excluding  value  of  by-products,  $1  less  $0.75 .25 

ESTIMATE  ON   BASIS   OF  CALIFORNIA   EXPERIENCE7 

Yield  average  12  tons  per  acre 

Yield  of  syrup  per  ton,  10  gals 120  gallons  per  acre 

Cost  of  concentrating,  etc $0.25  per  gallon 

Cost  of  cans  and  boxes 25  per  gallon 

Interest  on  plant,  10% 01  per  gallon 

Cost  of  cultivation,  irrigation,  Harvesting,  and  stripping 17  per  gallon 

Total  cost  $0.68  per  gallon 

Total  cost  per  acre 81.60 

Value  of  Products  per  Acre 

120  gallons  of  syrup  at  $1 $120.00 

1500  pounds  of  seed  at  3c,  for  feeds 45.00 

2400  pounds  of  leaves  at  $5  per  ton 6.00 

4  tons  of  pressed  «ane  at  $2.50  per  ton 10.00 

Total  value  $181.00 

Total  cost  81.60 

Net  profit  per  acre $99.40 

Allowing  no  interest  on  land  or  rent  charges. 

Uses  of  Sorghum  Syrup. — When  properly  made,  sorghum  syrup  is 
amber  in  color,  of  about  the  consistency  of  ordinary  table  syrup,  is 
usually  slightly  cloudy  or  opalescent  in  appearance  and  possesses  the 
pleasing  characteristic  flavor  of  the  sorghum  cane.  It  is  an  excellent 
table  syrup  for  use  on  hot  cakes,  biscuits,  etc.  It  can  also  be  used  as 
a  substitute  for  sugar  in  making  corn  bread,  cup  cakes,  and  in  similar 
ways.  When  diluted  with  water  it  may  be  used  for  canning  fruits  for 
home  use,  or  mixed  with  sugar  in  making  fruit  preserves.  Experi- 
ments with  other  syrups  would  indicate  that  sorghum  syrup  might 
also  be  used  as  a  sugar  substitute  in  jelly  making,  if  about  three- 
quarters  of  a  cup  of  the  syrup  is  used  to  one  cup  of  fruit  juice. 

7  Figures  for  yield,  cost  of  concentration,  and  boxes  are  based  on  estimates 
furnished  by  L.  B.  Bright,  of  Eiverbank,  who  has  made  syrup  on  a  small  scale 
for  three  years.     Other  figures  based  on  estimates  by  Adams  and  Madson. 

8  The  present  market  price  for  sorghum  seed  for  feeding  purposes  is  3^c 
per  pound.  Sweet  sorghum  seed  is  not  so  satisfactory  for  feeding  as  grain 
sorghum  seed.  For  seeding  purposes,  the  price  is  as  high  as  7c  to  8c  per  pound. 
Estimate  of  value  of  leaves  for  forage  was  given  by  Professor  P.  B.  Kennedy 
and  Dr.  F.  W.  Woll. 


16 


COMPANIES   FROM    WHOM    SORGHUM    SYRUP    MACHINERY 
CAN    BE   OBTAINED 

1.  Sears,  Roebuck  and  Company,  Chicago,  Illinois  (special  cata- 
logue of  farm  implements  and  machinery).  Mills,  open-pan  evapora- 
tors, and  furnaces. 

2.  Blymer  Iron  Works,  Cincinnati,  Ohio.  Mills,  open-pan  evapo- 
rators and  furnaces. 

3.  The  Bahmann  Iron  Works  Company,  Cincinnati,  Ohio.  Mills, 
open  evaporators  and  furnaces. 

4.  Golden 's  Foundry  and  Machine  Company,  Columbus,  Georgia. 
Mills,  open-pan  evaporators,  furnaces,  and  steam  evaporators. 

5.  Berger  and  Carter  Company,  San  Francisco,  California.  Steam 
evaporators,  pans,  mills  and  furnaces. 

6.  Cook  Cane  Mill  and  Evaporator  Company,  St.  Louis,  Missouri. 
Mills,  open-pan  evaporators  and  furnaces. 

7.  Montgomery  Ward  Company,  Chicago,  Illinois.  Mills,  pan 
evaporators  and  furnaces. 

8.  Chattanooga  Plow  Company,  Chattanooga,  Tennessee.  General 
equipment. 

9.  Southern  Plow  Company,  Columbus,  Georgia.  General  equip- 
ment. 

10.  A.  C.  S.  Bell  Company,  Hillsboro,  Ohio.     General  equipment. 


COMPANIES    FROM    WHOM    SYRUP    HYDROMETERS   AND    CYLINDERS    MAY    BE 
OBTAINED   IN   CALIFORNIA 

1.  Justinian  Caire  Company,  San  Francisco,  California. 

2.  Braun-Knecht-Heimann   Company,   San  Francisco,   California. 

3.  Bausch  and  Lomb  Company,  San  Francisco,  California. 

4.  F.  W.  Braun  Company,  Los  Angeles,  California. 

The  cost  of  hydrometer  and  cylinder  should  not  exceed  $1.50.  The 
hydrometer  should  be  used  to  insure  production  of  a  syrup  that  will 
not  ferment  or  crystallize.  Syrup  making  should  not  be  attempted 
without  it.  The  hydrometer  most  easily  obtained  is  a  Baume  hydro- 
meter with  divisions  from  0-50°.  A  glass  or  metal  cylinder  about 
iy2  inches  in  diameter  and  about  12  inches  tall  will  also  be  needed. 

It  is  urged  that  everyone  seriously  contemplating  the  manufacture 
of  syrup  during  the  coming  season  write  at  once  to  one  of  the  above 
dealers  and  make  contracts  for  delivery  of  machine.  The  University 
has  been  informed  that  there  is  apt  to  be  a  very  great  demand  for  this 
sort  of  equipment  and  that  contracts  should  be  made  at  once  to  avoid 
disappointment. 


